Process of and apparatus for manufacturing composite sheet material.



H. R. EDGECOMBJ PROCESS OF AND APPARATUS FOR MANUFACTURING COMPOSITE SHEET MATERIAL. APPLICATION FILED NOV. 25, 1914.

1 ,239,894:. PatentedSept. 11, 1917,

|NVENTOR j Hie/7% A? [Jyewmi ATTORNEY .UNHED STATESPATENT OFFER I HENRY n. EDGECOMB, on WILKINSBURG, PENNSYLVANIA, AssIoNoR T0 WEST NG I nonsnnnno'rnio AND MANUFACTURING COMPANY, A CORPORATION- or PENN- SYLVANIA.

Princess on AND APPARATUS FOR MAN FACTURING ooMPosITE SHEET MATERIAL:

To all whom it may concern:

Be it known that I, HENRY It. Enoncon'n, a citizen of the United States-and a resident of lVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a. new and useful Improvement in Processes of and Apparatus for Manufac-.

turing Composite Sheet Material, of which the following is a specification.

My invention relates to the manufacture of composite sheet material, and it has special reference to the manufacture of composite electrical insulating sheets; consistingol mica flakes and a binding material;

One ob ect of my invention is to provide process of automaticallybuilding up composite'material of the above-indicated chanactor in a continuous sheet and with a minimum expenditure of material, labor and time. Another object of my invention is to provide simple, convenient and eiiicient appa ratus for carryii'ig out my automatic process. The most successful method of building sheet mica insul' .tihg material, that bushel-e tolorc been emi iloyed consists in feeding measured amounts ofinica flakes and powdered binding material into the top oil {a relatively high tower, and allowing the mingled .l'lakes and binder to distribute themselves over the surface of a plate or box which forms the bottom of the tower. When sullicicnt material has been deposited in the receiving box to form a finished plate of the desired thickness, the box carrying the as semblcd mica and binder is -removed from the tower and the material is afterward subjected to heat andpress ure iuorder to melt the binder and cause the mica flakes to adhere firmly together. This process produces insulating sheets of excellent quality, but it has the disadvantage that it is relatively. slow and labor-consu1n1ng, on account oi: the

several manipulations that are necessary and the fact that the operations cannot be continuously performed.

According to my present invention, the process t lined above is made continuous by substi 'ing a slowly-moving belt for the plate or ho new employed to receive the shower of connningled mica flakes and bond.

" shown in Fig. 1. v The apparatus shown in the drawing comknife 7 Application filed November 25, 1914. Serial No. 873,956. i s i I This beltpasses underthe end of the tower, collects the fall-ingmaterial in a'continuous.

layer, and carries-the accumulated layer .to" 1 heated pressure devices whicliserve to inelt .55

the binder and compress the; micaintofa In the accompanying drawing, Figure 1,

Fig. 2 is a longitudinal sectional view of a mod fied form of a portion of the apparatus V firmly coherent plate, after which" the plate. is cooled and cut intosheets'of any desired. length. r i 6.0.; IS a longitudinal sectional-viewof apparatus.v suitable for carrying out my'process, and

prises amica building'tower 1, a belt 2,.

passing around rollers 3 and v4, a heating device 5, a cooling device 6, a shee't severing Y and a sheet-receiving table 8. The mica building tower may be of any suitable and well known constructionfsuch, for example, as that described and claimed in the patent to Sanborn, No. 1,074,57 6, granted September 30, 1 913 and assignedto Westing} house'Electric 61: Manufacturing Company.

As shown on the drawing, it consists of a j receiving hopper 9 for receiving a measured continuous supply of mica flakes, a. distr1but- ,ing hopper .10, an ejector 11 consisting of one or more air-blast nozzles for ejecting the mica flakes from the hopper 10, and a cylindrical sieve or bond distributor. 12

which is adapted to contain co'mminuted dry'. i I

fusible bonding material and to be rotated in any convenient manner for the purpose.

of sprinkling the powdered bond among the falling flakes of mica. i

The mica and bond 'fall uponthe belt 2,

which is preferably of metal and is. caused to advance slowly beneath the tower by means of power applied in any convenient manncrto the roller 3 or the roller 45. When the operation of the machine begins, the mica will be deposited upon the belt ina layer of gradually increasing thickness until the belt has advanced a distance equal to the width ofthe tower, after which the layen will be uniform in thickness until the ma chine stops, provided proper supplies of mica'are fed into the receiving hopper E).

In their descent in the tower 1, the flakes distribute themselves with remarkable uniformity, but some of the flakes may fall in an inclined position against the sides of the tower and thus make the edges of the sheet slightly uneven. In order to avoid such unevenness, a set of vertically moving fingers 13 are provided adjacent to the walls of the tower and are caused to reciprocate vertically in any convenient manner, as by means of a frame 14 disposed beneath the traveling belt and reciprocated bymeans of an arm 15 provided with a slot 16 that'is engaged b a pin 17 cccentrically mounted upon a dis 18 which is caused to rotate by means of a belt 19 passing around the roller 3 or a pulley coaxial withthis roller. It will be evident that the fingers 13 will reciprocate rapidly during the operation of the machine and will even the edges of the mica plate. At the outgoing edge of the tower, near the belt 2, is disposed a roller 20 which is spaced from the belt 2 by approximately the thickness of the mica plate being formed, andwhich is intended to smooth down any mica flakes which may have fallen on edge.

After the belt leaves the tower 1, it passes through a heating device 5. In the form of machines shown in Fig. 1, the heating device consists of an oven 21 heated by two heating elements 22 and 23, which may be sets of gas burners or electnichcating devices, and inclosing a pair of pressure members-24 and 2?), each of which, as shown, consists of a series of flat plates 26 joined at their ends and passing over pulleys or sprocket wheels 27. The operation of each of these pressure devices is similar to that of the well known caterpillar tractor. The

'form of heating device shown in Fig. 2

comprises the oven 21 and the upper pres-' sure members 24. but the lower pressure device 25 is replaced by a stationary metal platen 28. Either of the heating and pressing devices shovi'n serves to melt the comminutcd bond, expel any excess bond which may be present, and compress the mica flakes firmly together. After emerging from the oven 21. the belt 2 carries the micaplate to a cutting device, which is shown diagrammatically by the knife 7 and by which the plate is severed into sheets of any desired length. the sheets being received upon the table 8. If desired, the mica sheetmay be cooled by means of the device 6, which, as shown. consists of a pair of rollers 29 and 30 through which cooling fluid may be passed. As modifications of this cooling process. the rollers 29 and 30 may be replaced by a cooled pressure device similar in construction to the pressure devices 24 and 25, or the severed sheets may be placed in a cold press for a short time.

Several distinct advantages result from the continuous operation described above. The necessary apparatus occupies but little more space than is used in carrying out the existing discontinuous processes, and the handling and reheating of heavy iron plates is avoided. Furthermore, the amount of finished material that may be provided in a given time by a given number of operators may be greatly increased with no corresponding increase in labor costs.

According to a modification of the process set forth above, a web of paper is fed upon the surface of the belt 2 and caused to pass continuously beneath the tower 1, receiving the comminglcd mica flakes and bond as in the modification described above. If desired. the paper may be coated with liquid shellac or other adhesive material before being fed beneath the tower. and, in this case, the amount of comminuted solid bond to be used may be greatly reduced or such bond may even be entirely dispensed with. As will be evident from the foregoing discussion, my process and apparatus are capable of numerous modifications which are in part suggested above and which may be further devised by persons skilled in the art to which my invention appcrtains. In view of these variations of which my invention is capable. it is to be understood that it is not restricted to the precise manipulations andstructures disclosed above but is limitcd only by the scope of the appended claims.

I claim as my invention:

1. process of manufacturing sheet material that comprises distributing a shower of commingled flakemntcrial ,and a comminuted dry bond upon a continuously moving surface and applying heat and pressure to the saidmaterial while it is carried'by the said surface.

2. process of manufacturing sheet material that comprises distributing a shower of comminglcd mica flakes and a. comminuted dry bond upon a continuously moving surface and applying heat and pressure to the said material while .it is carried by the said surface.

' sure to the said material while it is carried by the said plane surface.

5. A process of manufacturing sheet material that comprises distributing a showerof conuninglcd flake material and a ronnninuted dry bond upon a continuously moving meried by the said surface.

7. A process of manufacturing sheet material that comprises distributing a shower of commingled flake material and a comvminuted dry bond'upon a continuously moving-surface, applying heat and pressure to the said material whileit is carried by the said surface, and thereafter cooling the same.

8. A process of manufacturing sheet material that comprises distributing a shower of commingled flake material and a comminuted dry bond upon a continuously moving metallic surface," applying heat and pressure to the said material while it is car-- ried by the saidsurface, and thereafter cooling the same while still carried by'the I said surface. g I

9. A process of manufacturing sheet material that comprises distributing a shower of commingled flakematerial and a comminnted dry bond upon acontinuously moving surface, applying heat and pressure to the said material while it is carried by the said surface, and thereafter cooling the same and severing it into sheets.

' '10. A process of manufacturing sheet ma terial that comprises distributing a shower of commingled flake material and a comminuted dry bond upon a continuously mov- 40 ing metallic surface, applying heat and pressure to the said material while it is carried by the said surface, and thereafter cooling the same while still carried by the said surface and severing it into sheets.

11. A process of manufacturing sheet material that comprises distributing a shower of commingled flake material and; a coming plane surface, flattening the said flake material upon the said surface, and applying heat and pressure to it while it is carried by the said surface.

12. A process of manufacturing insulating sheet material that comprises distributing a shower of commingled micav flakes and a comminuteddry bond upon a continuously moving metallic surface, applying heat and pressure to the said material while it is carried by the said surface,severing the said material into sheets and thereafter sub-;

- jecting the severed sheets to cold pressure. 13. A machine for making composite sheet material. comprising means for distributing a shower of commingled flake materialand a comminuted dry bond, a metallie sheet adapted to move adjacent to the said distributing meansand to receive the said commingled materiaL'and means for applying heat and .pressnreto the .said material while it is carried by the said sheet.

14:. A machine for ,making' composite sheet material comprising means for distributing a shower of commingled flake material and a comminuted dry bond, at metallic belt adapted to move continuously and to receive the said commingled material,

means for flattening the said material upon the said belt, and means for applying heat a and pressure to the said material while it is carried by the said belt.

15. A machine for making composite sheet material comprising means for distributing a shower of commingled flake material and a comminuted dry bond, a metallie belt adapted to. move continuously and to receive the said commingled material, means for applying heat and pressure to the said materiali -while it is carried by the said belt, and means for cooling the said heated and pressed material.

16. A machine for making composite sheet material comprising means for distributing a shower of commingled flake material and a comminuted dry bond, a-metal lic belt adapted to move continuously and to receive the said commingled material, and means for applying heat and pressure to the said material. while it is carried by the said belt, thesaid means comprising an oven, cooperating pressure members within the said oven, andmeans for heating the said oven.

17. A machine for making composite sheet material tributing a shower of commingled flake material and a comminuted dry bond, a belt adapted to move continuously and to receive the said commingled material, and means for applying'heat and pressure to the said material while it is carried by the said belt,-the

oven, at least one of the said pressure members being adapted to move with the said material, and means for heating the said oven.

18. A machine for making composite comprising means for dis said means comprising an oven, co-

operating pressure members within the said minnted dry bond upon a continuously movsheet material comprising means for distributing a shower of commingled flake material and a comminuted dry bond, a belt adapted to move continuously and to receive the said commingled material, and means for'fla'ttening the said material upon the said bolt, the said means comprising vertically-reciprocating cent to the said belt.

19. A machine for making composite sheet material comprising means for distributing a shower of commingled flake materm] and a comminu'ted dry bond,a belt adapted to move continuously and to receive the said commingled material, and means for flattening the said material upon the said belt, the said means comprising vertically-reciprocating fingers disposed adjacent to the said belt, and a roller adapted to engage the surface of the said material.

20. A machine for making composite sheet material comprising means for distributing a shower of commingled flakel material and a comminuted dry bond, a belt adapted to move continuously and to receive the said commingled material, means for applying heat and pressure to the said material While 1t is carried by the said belt, 15

means" for cooling the said heated and HENRY R. EDGECOMB.

Witnesses:

GoLnm E. MoGEE, B. B. HINEB. 

